package Inherit;

import java.security.PublicKey;

public class Test {
    public static void main(String[] args) {
        Animal a = new Animal();

        Dog d =new Dog();

        Bird b =new Bird();


    }
}

class Animal{
    public int age;
    public void sleep(){

    }
}

class Dog extends Animal{
    public String tooth;
    public void run(){

    }

}

class Bird extends Animal{
    public String feather;
    public void swing(){

    }

}